[RESOLVED] MS Sql Server - not filtering on Null?

[Ecniv]

Hi,

Got a weird one. I have two simple sql statements.

select top 10 * 
  from tablename
 where idfield is null
 
SELECT top 10 
       pb.*
  from tablename pb

The first returns no records.
The second returns ten records, of which the idfield is null.

Any ideas why MS Sql server isnt filtering correctly?